The history of radars in Russia.
thumb|300px|right|Radars A radar station or a radar ( radar from Radio Detection And Ranging) is a system for detection of air, sea and ground objects, and also for definition of their range and geometrical parameters. Basic units are transmitting and reception devices located in be item. In a passive radar-location, the transmitter is absent. The aerial can be both for the transmitter and the receiver. The basic characteristics are weight, dimensions, capacity of power supplies, service life, quantity of the attendants and many others. The first experiments on radiodetection of planes were made by the USSR in 1934. Industrial manufacturing of the first military radars began in 1939. The Radio Detection And Ranging stations , with the continuous radiation modulated by sound frequency, settled down a chain along some line and allowed to find out planes crossing this line. They have been applied on Karelian isthmus during the Soviet-finnish war 1939-40 and on Caucasus during the Great Patriotic war 1941-45. The first pulse radar-tracking installation was tested in 1937. Industrial manufacturing pulse Radio Detection And Ranging stations began in 1940. These stations had transferring aerial and were located together with a source of power supplies in a body of a motor vehicle. They allowed to find out planes at the circular review of air space on distances up to 150 km. In 1940 at Leningrad physicotechnical institute (the head of works-J. B. Kobzarev) the construction of stationary system of air defence was completed Aerials of station were settled down at the big height (20, that provided greater range of detection (250 km) and enabled to find out rather low flying planes. During the Great Patriotic war, except for stations " Reduts ", manufacture of reliable portable stations " Pegmatid " which could be transported easily in the packed kind has been developed. Subsequently stations " Pegmatid " have been so advanced, that they allowed to define, except for range and an azimuth of self-summer, its height. In the end of war perfection occured in a direction as increases of range of their action and accuracy of measurements, and automation of separate operations by means of automatic watching systems for measurement of range and tracking on angular coordinates, automatic the account devices (in stations for "blind" bombing), etc. After the World War II , with the development of aircraft (increase of height, speed of flight and a maneuverability of planes), there appeared the necessity of creation Radio Detection And Ranging systems capable to work in complex conditions - at a plenty of objects and action of deliberate handicapes. Increase of accuracy of measurement of coordinates (including owing to new methods of their measurement), interface to computers and the general system of radiomanagement of shells-rockets was essentially changed with the technical and tactical parameters become the major part of the automated control system by means of air defence. Rocket and space technologies appeared in 50-60,which led to creation for the decision of some new problems Radio Detection And Ranging systems: Radionavigating system, the Meteoric radar, the Planetary radar, Radar-tracking astronomy, the Radar-location in meteorology, etc. Category:Science and technology